From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Data table showing efficiency ratios from starter motor tests.
| Identifier | ExFiles\Box 64\1\ scan0275 | |
| Date | 14th June 1928 | |
| STARTER MOTOR TESTS. FORM 5. EFFICIENCY RATIOS. C2 2s 2p | C | ϕE | ϕe | ϕB | ϕT | ϕe/ϕE = es/E | ϕT/ϕB = Tr{Capt. F. W. Turner - Finance}/Ts | ϕT/ϕE = η | ϕB/ϕe | |-----|-----|-----|-----|-----|--------------|---------------|-----------|-------| | 20 | | | | | | | | | | 30 | | | | | | | | | | 40 | | | | | | | | | | 50 | 118 | — | 88 | 26 | .745 | .296 | .220 | — | | 60 | 126 | — | 94 | 36 | .745 | .383 | .286 | — | | 80 | 139 | — | 108 | 55 | .778 | .509 | .395 | — | | 100 | 155 | 141 | 118 | 73 | .762 | .618 | .471 | .837 | | 120 | 169 | 152 | 126 | 85 | .746 | .674 | .502 | .829 | | 140 | 189 | 163 | 130 | 95 | .688 | .730 | .503 | .797 | | 160 | 205 | 174 | 134 | 103 | .654 | .768 | .502 | .770 | | 180 | 222 | 180 | 137 | 108 | .617 | .788 | .487 | .761 | | 200 | 244 | 187 | 140 | 112 | .573 | .801 | .458 | .748 | | 220 | 271 | 194 | 142 | 117 | .524 | .823 | .432 | .732 | | 240 | 312 | 200 | 145 | 120 | .465 | .828 | .385 | .725 | 14.6.28. | ||